This invention relates to a vertical fine adjustment mechanism (focusing mechanism) for optical microscopes including optical measuring instruments.
A mechanism in which the objective lens moves vertically along the Z-axis is frequently used as the focusing mechanism in conventional optical measuring instruments and optical microscopes.
The structure of conventional microscopes is described briefly referring to the drawings. Figure 4 is a side view of the principal part of a microscope and Fig. 5 is a plan view of it. In the drawings, (101) is a stand, (102) is a support mounted on the stand (101) for free vertical movement, (103) is a revolver for the objective lens mounted on the support, and (104) is the objective lens mounted on the revolver. At the support (102), a V-groove (105) for a vertical straight movement guide mechanism is formed on both sides as shown in Fig. 5, and opposite to this groove, a V-groove (106) for a vertical straight movement guide mechanism is formed on the stand (101), and a roller or a ball (107) is held between these two grooves. Also a rack (108) is mounted on the support (102), a shaft (110) with a pinion (109) engaging this rack (108) protrudes from the stand, and an operation handle that is not shown is mounted on this protruded portion. When this operation handle is rotated, the pinion (109) is rotated through the shaft (110), the rack (108) mounted on the support (102) moves vertically, and also the support (102) moves vertically at the same time, allowing the objective lens (104) mounted on the revolver (103) to be focused.
In the conventional microscopes described above, however, since one end of the one side support type support (102) that is asymmetrical with respect to the center of the optical axis is moved vertically for fine adjustment by means of the rack-and-pinion mechanism, the vertical fine movement mechanism is remarkably asymmetrical and the operation is unstable. Variations in environmental temperature, in particular, cause fluctuations of the center of the optical axis, resulting in the unstable image. Since drift due to temperature changes occurs in such a vertical fine movement mechanism, this mechanism cannot be currently used for molecular position measurement or molecular motion measurement.
This invention is therefore intended to solve the above problem by realizing an optical microscope of high stability in which the image of the viewed sample does not become out of focus during observation and no movement (drift) of the object point (object) occurs.
Viewed from a first aspect, the present invention provides a vertical fine adjustment mechanism for microscopes according to claim 1.
A preferred embodiment provides a vertical fine adjustment mechanism for microscopes including two of said interlock pins configured so that uniform strain is applied to both.
A preferred embodiment provides a vertical fine adjustment mechanism for microscopes wherein said actuator is a micrometer.
Preferred embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings in which:
The embodiments of the vertical fine adjustment mechanisms for microscopes relating to this invention are described with reference to the drawings. Figure 1 is a side sectional view of said microscope, Fig. 2 is a plan sectional view of the same microscope, and Fig. 3 is a side view of the same microscope.
In the drawings, an external cylinder (2) that has concentric inside diameter and outside diameter around the central axis is mounted vertically on the substrate (1). At the lower part of the external cylinder (2), flange (2A) for fastening is formed, and in the inside diameter of the external cylinder (2), an intermediate cylinder (3) is incorporated with very small clearance. Parallel cut-out surfaces (4A) that are parallel to the central axis of this intermediate cylinder (3) and are set at equal distances from this central axis are prepared at 120 degree intervals, and V-shape groove straight guide hardware (4) is mounted on these cut surfaces so that the hardware can be tightened with fastening screws (5). On the equally three-divided portions of the inner circumference of the intermediate cylinder (3), a rectangular window is opened in which a roller or a ball (8) rolls.
On the equally three-divided portions of the outer circumference of the internal cylinder (7) to which the objective lens (6) of the microscope can be mounted by screwing it on, a V-groove in which a roller or a ball (8) rolls is cut.
A vertical straight movement guide mechanism (three-directional straight guide mechanism) with a hollow shaft (optical axis) is configured by assembling these parts. In addition, this mechanism can be configured so that two of three V-grooves formed in equally three-divided portions of the outer circumference of the internal cylinder (7) are square groove (that is, the groove surface is flat), the relevant parts of the intermediate cylinder (3) are planes parallel to the central axis, and a roller is incorporated between them. In this configuration, although symmetry is slightly impaired, the stability is not affected and the manufacturing cost can be reduced.
Also in this configuration, the V-shaped groove straight guide hardware (4) is fastened with screws (9) on the outer circumference of the external cylinder (2) at 120 degree intervals to prevent unstable movement of the intermediate cylinder (3), and to enable pressure to be applied to the roller or the ball (8).
The mechanism for applying pressure is not limited to the screws (9) described above, and the following configuration can also be adopted. If operating temperature fluctuations exceed several degrees, even if material of the same thermal expansion coefficient is used, for example, for the intermediate cylinder (3) and the internal cylinder (7), some fluctuation may occur, resulting in fitting instability that exceeds deformation levels due to pressure or excessive pressure. In this case, a configuration can be adopted in which coil springs and spring housings are prepared in place of the screws (9) on the external cylinder (2), or plate springs are inserted between the intermediate cylinder (3) and the V-shaped groove straight guide hardware (4), to absorb the fitting instability caused by operating temperature fluctuations while maintaining the symmetry. Also a coil spring can be used as the spring, and other types of springs that can achieve a similar function can be used in place of the plate spring.
On the other hand, the vertical fine movement mechanism can be comprised of a means of fine adjustment that is comprised of the interlock pin (10), the micrometer head (11), and a lever with inverted L-shaped hardware. The interlock pin (10) is mounted on the internal cylinder (7) to which the objective lens (6) is mounted, and one side of the inverted L-shaped hardware (12) contacts this interlock pin. The inverted L-shaped hardware (12) is supported for free rotation in both directions through the washer (14) by the fixed shaft (13) that is mounted on the outer circumference of the external cylinder (2), and the other side of the inverted L-shaped hardware contacts the micrometer head (11). The micrometer head (11) is mounted with the micro-fixing hardware (15) so that its height is aligned with that of the inverted L-shaped hardware (12), and the operation of the micrometer head (11) allows one side of the inverted L-shaped hardware (15) to be pressed, the other side of the inverted L-shaped hardware to be moved upward accordingly, and the interlock pin (10) to be pushed up to move the internal cylinder (7) upward with fine adjustment. Also the rotating section of the inverted L-shaped hardware can be equipped with a return spring if appropriate to enable it to be restored to its initial state. In addition, for the micrometer head (11), another actuator with a gear motor can be used. Also the level of fine adjustment can be set freely by adjusting the length of each side of the inverted L-shaped hardware.
The preferred embodiments of this invention are as described above. However, the vertical straight movement guide mechanism is not necessarily limited to three directions, and other numbers of directions are possible. Also other types of vertical fine movement mechanisms that can realize similar action can be used by changing the shape of the grooves and the roller.
In addition, this invention can be embodied in any forms without deviating from its purpose or principal features. The preferred embodiments described herein are therefore only examples in all respects and should not be construed to imply limitations.
The straight guide mechanisms of this invention have symmetrical structures with respect to their weight and shape, and therefore, a microscope focusing mechanism with very good balance and high stability is achievable.
Since a highly stable optical microscope is realized, measurement of molecular position and molecular motion on the order of nanometers in the fields of molecular biology and biophysics can be easily performed. If an actuator with 0.1 µ per pulse that has the high degree of straightness and low torque required for vertical fine movement is used at the micrometer head (11) in the straight guide mechanism, the leverage enables a highly precise and low-cost vertical fine movement mechanism capable of achieving resolutions of 0.02 µm or less.
These effects can be achieved as described above.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.